Jambojet has flown 2.5 million passengers in its four years of operations, the airline said in a statement on Monday.
The firm said it will have a 72-hour special fare of Sh3,000 one-way for 7,000 seats to all its Kenyan destinations.
This is close to a 33 per cent discount on its lowest fare which is usually Sh4,500.
CEO Willem Hondius said it was a breakthrough for the airline to hit such a major milestone.
He said Jambojet reached its 1 million passengers milestone in February 2016.